Applications requiring light energy and, in some embodiments, laser energy, may benefit from the use of solid state light sources such as laser diodes which are commonly available, reliable to operate and relatively cost effective as a laser energy source. Such devices may include a plurality of laser emitters in a single bar that each emit laser light simultaneously in a substantially parallel orientation. In addition, multiple solid state or laser emitter bars may be disposed in a stacked configuration so as to generate even higher power levels in some instances. Laser diode bars are often used for communication technology devices, medical applications and other applications such as military applications. For some of these applications, as well as others, it may be desirable to couple the output of all the emitters of a single solid state emitter bar or multiple bars in a stacked configuration into a single optical fiber or other optical conduit.
In some circumstances, coupling laser radiation from a linear array of multiple discrete emitters into an optical conduit may result in a non-homogeneous output from the optical conduit in the far field pattern emitted from the optical conduit. Such a non-homogeneous far field pattern may result from the discrete angular distribution of the multiple emitters being coupled into the optical conduit relative to a longitudinal input axis of the optical conduit. This may be particularly true in optical system embodiments which require each beam to be spaced from adjacent beams while propagating through at least some of the optical components of the optical system. For some systems, the separation includes gaps between adjacent beams which may then result in discrete launch angles for each beam or set of beams into the optical conduit. The discrete launch angles into the optical conduit generate a non-homogeneous far field pattern of emission from the optical conduit. This type of far field pattern may include low intensity regions that cause inefficient coupling or transmission of the light in the far field. In addition, this type of far field pattern may include high intensity regions or hot spots that may cause damage to materials with which the far field beam interacts.
What has been needed are methods and devices for generating a homogenous or substantially homogeneous far field beam distribution for the output of an optical conduit. More specifically, what has been needed are methods and devices for generating homogeneous far field beam patterns from an optical conduit from an input source with multiple beams having discrete launch angles.